Cummins 5.9 Head Gasket Concerns

JHZR2

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With the good comes concerns sometimes; hopefully much ado about nothing…

Bought this 96 Ram CTD. Drove it around SD a ton. No issues. Few hundred miles. Then, we drove it across SD at speed, some on the BIA 2 and SD 73, but mostly on the I-90, which has a limit of 80 MPH. So about 245 miles at high speeds. Checked everything underhood after the high speed run, and it went from this:
68C8F620-FED4-493B-B5ED-230394C639CC.jpeg

To this:
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Closer up:
F5665D75-4145-45DF-B16D-4A1EC29B9FB5.jpeg
524539DD-38C7-4A47-B261-4ECA856991B1.jpeg

Anti freeze on some of the heater core pipes and other areas. There’s lots going on in that area, and it’s a known location for the HG to leak overboard. But the evidence doesn’t point abdolutely to a HG failure.

I cleaned up most all residues. Verified coolant, which was about 1cm below the fill hole in the neck, and at “full” in the overflow.

Fast forward 1200 miles, and today I saw similar residues. I didn’t recall seeing them any days in-between, but today’s operations had higher levels of hills and speed as I progressed through western PA. To my disappointment I saw this:

494CC32B-7890-47FE-A3BE-8CC0F56458A5.jpeg

Yeah, more antifreeze splatter.

And more spots.

FAAF165C-1AEB-4229-8792-B18CAAF1AC04.jpeg
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So, the HG is known to fail and leak overboard in some conditions, specifically in that corner. Similarly, the thermostat housing is real close in that area.

But no specific point of leakage. Where this was coming from is a mystery.

I checked it a few times when stopping for breaks. One quick stop after a hard, fast run, I noted this:


Cant tell if it’s bubbling out of the exhaust ( why would it?), or if it’s just the glycol bubbling on a hot surface. OK, so now a bit more worried. Let temperatures drop, and went to open the systems compare collant height. It was full in the overflow. OK. So whats the matter? The coolant is clean, and seemingly working well. Temperatures are always under control, no concerns.

But the residues come in the area with a lot of coolant related stuff (pump, etc., and, the head gasket could be an issue. But not the only one. So I kept driving, stopping quickly after a hard run to check. Only ever saw some dried residues, not fresh water .

After about 1200 miles we stopped to check, and Inhad to add water. The amount needed is about a quart.


DCD5CD9D-A0A7-48BC-BB80-1BCBDCA0AAF5.jpeg


You can see it wanted to run down from something in that area.
B6EFAE05-ADE5-411C-A2F9-9DC856E38FA2.jpeg




So at this point I’d like to be able
to diagnose. What’s the best bet? A pressure test of the cooling system? Licking of the records?

I can go to HF and get a universal cooling system tester. A bit expensive but not horrible, and looks decent. I can do UOA. What else should I do to absolutely determine if it’s an issue with the HG versus the t-stat or some other exterior housing?

Id like to get to the bottom of if I have a compromised HG. Folks have reported foing long distances with them seeping out. We will see. I’d still like to know what I’m dealing with.

Any thoughts and ideas would be great.
 
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Definitely use engine de-greaser and pressure test. Are there any cracks in the block? I don't think i've ever seen a leak quite like that one. Good luck please post back now I'm curious.
 
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Check the Head Bolts in the area.....My '97 Ram popped the heads right off 2 head bolts that would only leak coolant after a hard (Boosted) run uphill.

I was lucky enough to replace the 2 head bolts after sucking all the coolant out on the bolt holes & got another 60,000 or so miles out of her before trading it in.

Mine was uprated with a TST 230/605 kit though....Which fueled pretty hard at low boost.
 
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My 96 had a TST 275/675 #11 Plate. It would do the exact same thing pulling hard uphill while towing. I could keep it from leaking by taking it easier on the hills while towing. I was able to nurse it along for several years till I sold it.

It's a common problem and the proper fix is to replace the head gasket with the upgraded marine version. They might not even sell the weaker factory gaskets anymore.
 

JHZR2

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Check the Head Bolts in the area.....My '97 Ram popped the heads right off 2 head bolts that would only leak coolant after a hard (Boosted) run uphill.

I was lucky enough to replace the 2 head bolts after sucking all the coolant out on the bolt holes & got another 60,000 or so miles out of her before trading it in.

Mine was uprated with a TST 230/605 kit though....Which fueled pretty hard at low boost.

Im assuming that the best move is to torque ALL bolts, or at least all that I can reach with the engine in the truck and the fuel system installed… in the order and to the level indicated by the FSM?

196F77B8-40EC-4F20-AFA2-0FF146E4AFBB.jpeg

Or should I just do #20 and 24? Or maybe #20, 24 and some neighbors on both sides of the block?

Otherwise what’s the sign that it popped the head off the bolt? None are missing or just sitting there loose, fwiw.

My 96 had a TST 275/675 #11 Plate. It would do the exact same thing pulling hard uphill while towing. I could keep it from leaking by taking it easier on the hills while towing. I was able to nurse it along for several years till I sold it.

It's a common problem and the proper fix is to replace the head gasket with the upgraded marine version. They might not even sell the weaker factory gaskets anymore.

Yes it seems that this only has happened when pulling hard uphill and at speeds over 75 mph. That puts the engine at a sustained speed over 2250 RPM fwiw, and Im sure the water pump is pushing a lot of fluid. But my concern really is that we were traveling lightly loaded. No towing, not that hot. My need to cruise at 80 mph is very limited. Maybe it’s just not prudent even out west For this truck/engine. That’s very much ok. I just want to be proactive.

I wouldn’t be opposed to a new HG in this truck/engine, but I’d also rather not spend money that I don’t need to.
 
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I wouldn’t be opposed to a new HG in this truck/engine, but I’d also rather not spend money that I don’t need to.
I can certainly understand that however, if it is doing it on routine drives then it may be worth it to you to fix it.

fwiw, on mine I checked the torque on head bolt's in the leak area and all of them were ok.

It is not the coolant pressure that is causing it, it is the cylinder pressure under high loads that is lifting that corner of the head. Supposedly leaving it in this condition (so I have read) can cause erosion on the head/block mating surfaces leading to more costly repairs.

Another issue with these engines is exhaust manifold shrinkage. If you look at the outside exhaust manifold bolts, they should be centered. If they are pushed off to one side then you manifold has shrunk. This causes higher exhaust back pressure and in some cases can break the mounting ear off the head. I replaced mine with an aftermarket 3 piece manifold.
 

JHZR2

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I can certainly understand that however, if it is doing it on routine drives then it may be worth it to you to fix it.

fwiw, on mine I checked the torque on head bolt's in the leak area and all of them were ok.

It is not the coolant pressure that is causing it, it is the cylinder pressure under high loads that is lifting that corner of the head. Supposedly leaving it in this condition (so I have read) can cause erosion on the head/block mating surfaces leading to more costly repairs.

Another issue with these engines is exhaust manifold shrinkage. If you look at the outside exhaust manifold bolts, they should be centered. If they are pushed off to one side then you manifold has shrunk. This causes higher exhaust back pressure and in some cases can break the mounting ear off the head. I replaced mine with an aftermarket 3 piece manifold.

That’s the thing. 80MPH on a run halfway across the country on I-90 isnt routine. 70MPH roads like the PA turnpike didn’t seem to create the issues unless driving hard up and down the mountain passes in western PA. But again, unloaded truck.

I have hauled pretty heavy in my other CTD. It has a more convenient bed for carrying significant loads. TBD if I’ll do the same on this one, but I want it to be able to pull an RV without issues or concerns. But that’s some time out at this point.

I have also read that leaving it can result in an erosion issue. Don’t want that. I did pick up a pressure test kit. I’m thinking that assuming it holds 16psi, that I don’t have an erosion issue, and it’s the head lifting issue only. I have read that some folks have re-torqued to 115 or 125 ft lb, but I’ll think about that later. If I don’t have a leak, and drive mainly on less steep, slower conditions, I have time to plan my next moves. Maybe it is bite the bullet, maybe not. I don’t want to increase power at this time, so not sure studs are necessary, but also don’t want to encounter this same issue down the line.

I appreciate the info on the manifold shrinkage. I’ll look into that too…
 
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Be aware the more than likely the head is going to require resurfacing. I’d pull it apart and fix it. It’s only going to get worse, how fast it progresses is anyone’s guess. JMO
 

JHZR2

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You could replace the head bolts one at a time.

I would personally do a new gasket with ARP hardware.
Studs are a whole new can of worms, including needing to machine the rocker towers and whatnot.

I think I’d go with new bolts and new gasket, not sure about studs. I’m not turning up the fuel. The tamper proof screw is still on my IP. But I could be convinced.

Im starting with a pressure test and combustion gas test and will go from there. Other than maybe 150 miles of hauling, I have no pressing need to drive this truck long distances at the moment. While I’d like to, I don’t have to. So I can be deliberate and take my time on this. I’d actually like to DIY, but I am concerned about the time and distraction from other work.
 
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Is the valve cover supposed to have a gap at the corner like that?
That's just an aluminum cover slapped on top of the engine so they could put the "Dodge" name on it. Looks like the rubber grommets have seen better days.

Mine wound up in the trash.
 

JHZR2

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I did a pressure test, held 15 psi, but it seemed like I saw some dampness where the glycol already was.

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When I pulled the pressure tester a bunch of coolant shot out, so I rinsed the whole engine off. Then took it for a drive. Much cleaner, and it seems to be at the head interface.

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But especially this last image has me wondering if maybe it’s the rear gasket between the lifting eye bracket and the block….


Would sure be nice if it was that and not a HG!

Im going to check the torque of the thermostat bolts tomorrow.
 
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Im assuming that the best move is to torque ALL bolts, or at least all that I can reach with the engine in the truck and the fuel system installed… in the order and to the level indicated by the FSM?

View attachment 70310
Or should I just do #20 and 24? Or maybe #20, 24 and some neighbors on both sides of the block?

Otherwise what’s the sign that it popped the head off the bolt? None are missing or just sitting there loose, fwiw.



Yes it seems that this only has happened when pulling hard uphill and at speeds over 75 mph. That puts the engine at a sustained speed over 2250 RPM fwiw, and Im sure the water pump is pushing a lot of fluid. But my concern really is that we were traveling lightly loaded. No towing, not that hot. My need to cruise at 80 mph is very limited. Maybe it’s just not prudent even out west For this truck/engine. That’s very much ok. I just want to be proactive.

I wouldn’t be opposed to a new HG in this truck/engine, but I’d also rather not spend money that I don’t need to.

#22, #25, & #26 are the ones I would check, Should easily take 100 foot pounds.

Mine popped #25 & #1, I caught mine very quickly as I was almost to work after pulling quite a grade at full tilt with a loaded 40' gooseneck.....I shut her down & soon as I got out I smelled antifreeze. #25 bolt head was gone & #1 bolt head was captured between the 2 valve covers. Just stopped pushing as hard cause that truck was beginning to nickel & diming me to death.

If the bolts check out....Go ahead & install a new thermostat as it likely needs one anyway & reseal the housing. Pressure test it again.

Wouldn't at all be surprised if you need a Head Gasket though.....As legendary as the 12 valve B-Series is.....A Leaky Head Gasket was fairly common. Like Mattd said.....Have the head surfaced! Use the latest Cummins bolts & gasket upon reassembly.
You don't need studs at stock power levels.
 

JHZR2

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#22, #25, & #26 are the ones I would check, Should easily take 100 foot pounds.

Mine popped #25 & #1, I caught mine very quickly as I was almost to work after pulling quite a grade at full tilt with a loaded 40' gooseneck.....I shut her down & soon as I got out I smelled antifreeze. #25 bolt head was gone & #1 bolt head was captured between the 2 valve covers. Just stopped pushing as hard cause that truck was beginning to nickel & diming me to death.

If the bolts check out....Go ahead & install a new thermostat as it likely needs one anyway & reseal the housing. Pressure test it again.

Wouldn't at all be surprised if you need a Head Gasket though.....As legendary as the 12 valve B-Series is.....A Leaky Head Gasket was fairly common. Like Mattd said.....Have the head surfaced! Use the latest Cummins bolts & gasket upon reassembly.
You don't need studs at stock power levels.

Thanks. Driving it just around town the last few days, any signs of moisture at the Head/block interface have gone away. Everything is just so tight in there, it’s hard to see what’s what. I’m thinking to clean it all again, try to watch where it is coming from, and re-seal the thermostat first. Hoping it is just that, maybe seepage behind the lifting eye. It would be nice to not do a HG right now given a number of other things I’d like to do…
 

JHZR2

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Still can’t verify the source - HG or thermostat housing.

Cleaned things up as best as I could with a toothbrush and steel wool. It’s tight in there.
1F9E6A92-1A0D-40B0-9CA6-93E4A7E4795C.jpeg


Did about 70 miles of driving, half at about 70 MPH, half around 55 stop and go.

Then saw this:

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Very frustrating that I can’t tell where this is actually coming from. Any thoughts based upon these images?

Again, not opposed to putting a HG on it, but might start with the thermostat assuming I can get the bolts loose…


Thoughts?
 

JHZR2

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To me, all the wet areas are around the head gasket, not the thermostat housing.

The only thing is the residue on the far side of the thermostat housing. The one place where there is less bolted support, and it is a sandwich of metal with two seals.

I do also notice that the temperature fluctuates more on this one (I know it’s considered “normal” on these), and I hear the fan clutch engaging fully. Both things I never notice on my other 96 2wd truck, which if anything has more heat load due to the AT cooler in the mix…
 
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